| FIGURE A |
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| Fig A—A 10-MHz carrier amplitude modulated by a 6-kHz signal has a bandwidth of >10 MHz (a), but the actual information bandwidth is 12 kHz. By undersampling at exactly the Nyquist frequency (b), the information signal is "folded" into a series of aliases beginning at the baseband. Oversampling beyond the minimum Nyquist frequency spreads the aliases apart (c), reducing the cutoff demands on circuit filters. |
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